1. Field of the Invention
This invention relates to a technique of estimating the timing of failure of a product including plural components and the degree of degradation of each component, and reflecting them onto a maintenance schedule.
2. Description of the Related Art
Conventional maintenance scheduling is based on the experience and intuition of individual servicemen. Therefore, the risk of damage to a user caused by the unavailability of a product and the maintenance cost cannot be balanced with each other.
That is, if a component that is very likely to have failure is replaced before the end of its life in order to reduce the risk of product failure, the replacement operation takes place more than necessary and increases the maintenance cost. Conversely, if a component is used up to its full life in order to lower the maintenance cost, the component is replaced after failure occurs. Therefore, the downtime is long and the damage to the user caused by the unavailability of the product increases. Such trade-off relations exist.
A technique of setting a maintenance schedule based on the cost and risk is disclosed. In this technique, whether to carry out maintenance or not is determined on the basis of the risk, but which component is to be replaced is not determined (see JP-A-2004-152017).